feat(ugc): settings for the ray tracer, hidden-face method and denoising

New UGC settings (ugcconfig.ini and the dashboard's settings page):

- ray_backend: builtin (default), embree or hiprt (falls back to embree when
  the build or machine can't); the hidden faces' paths and the occlusion rays
- hsr_method: toolbox (default, LU Toolbox's paths) or fast (the renders from
  around the model), and hsr_fast_resolution (1024) for the fast one
- denoise: off (default) or oidn (icons; off until a build has it)

UgcProcessOptions (dCommon/UgcKeys.h) names the choices for everything that
passes them on ("embree fast oidn", any order, left out: the setting's).
UgcJobs::ApplyOptions puts a choice over the settings and MadeWith says what a
make used after fallbacks; a made model's stats.json records it (rays,
hsrMethod, denoise). UgcServer --make-model and --make-modular take the
choices after the folder and print the CPU time and what made it.

Check: the defaults make the same files as before; the settings page shows the
four settings under UGC; UgcServer --make-model model.lxfml out embree fast.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

resources/ugcconfig.ini

@@ -140,6 +140,17 @@ hsr_samples=8
 hsr_bounces=8
 hsr_sample_spacing=0.1143
 hsr_min_points=28
+# hsr_method: toolbox (LU Toolbox's paths, above) or fast (renders from 42 directions around the model, hsr_fast_resolution
+# pixels square; much faster, but it also removes faces seen only by bounced light).
+hsr_method=toolbox
+hsr_fast_resolution=1024
+
+# What traces the rays of the hidden faces' paths and of the occlusion: builtin, embree (Intel Embree on the CPU) or
+# hiprt (the GPU, when built with DLU_HIPRT and the machine has one; else embree).
+ray_backend=builtin
+
+# denoise: off, or oidn (icons cleaned up with Intel Open Image Denoise, when built with DLU_OIDN; else off).
+denoise=off
 
 # Bake ambient occlusion into the vertex colors: rays per vertex, how far they look, strength 0 (none) to 1, and how
 # much glowing colors add